utime

Documentation

Index

• Variables
• func GuessTimeFreq(ctx context.Context, ts *dataframe.SeriesTime, opts ...GuessTimeFreqOptions) (string, bool, error)
• func NewSeriesTime(ctx context.Context, name string, timeFreq string, startTime time.Time, ...) (*dataframe.SeriesTime, error)
• func ValidateSeriesTime(ctx context.Context, ts *dataframe.SeriesTime, timeFreq string, ...) error
• type GuessTimeFreqOptions
• type MissingValueOption
• type NewSeriesTimeOptions
• type NextTime
• type TimeGenerator
  • func TimeIntervalGenerator(timeFreq string) (TimeGenerator, error)
• type ValidateSeriesTimeOptions

Variables

var (
	// ErrContainsNil means that the SeriesTime contains nil values.
	ErrContainsNil = errors.New("contains nil")

	// ErrNoPattern means that no pattern was detected.
	ErrNoPattern = errors.New("no pattern detected")
)

var (

	// ErrCantValidate means that the validation algorithm could not determine whether the Series was in the reverse direction or not.
	ErrCantValidate = errors.New("can't validate")

	// ErrCantReplace means that the Validation algorithm was not able to determine what a missing value should be replaced as.
	ErrCantReplace = errors.New("can't replace")

	// ErrValidationFailed means that validation of the SeriesTime failed.
	ErrValidationFailed = errors.New("validation failed")
)

Functions

func GuessTimeFreq

func GuessTimeFreq(ctx context.Context, ts *dataframe.SeriesTime, opts ...GuessTimeFreqOptions) (string, bool, error)

GuessTimeFreq will attempt to guess the time interval in a SeriesTime. It will return a string that is compatible with TimeIntervalGenerator. It will also return a bool indicating whether the sequence is in reverse.

Due to daylight savings and varying days per month, it is not always possible to determine a pattern with 100% confidence.

NOTE: As currently implemented, nil values are not tolerated.

func NewSeriesTime

func NewSeriesTime(ctx context.Context, name string, timeFreq string, startTime time.Time, reverse bool, opts NewSeriesTimeOptions) (*dataframe.SeriesTime, error)

NewSeriesTime will create a new SeriesTime with timeFreq prescribing the intervals between each row. Setting reverse will make the time series decrement per row.

See https://godoc.org/github.com/rocketlaunchr/dataframe-go/utils/utime#TimeIntervalGenerator for setting timeFreq.

func ValidateSeriesTime

func ValidateSeriesTime(ctx context.Context, ts *dataframe.SeriesTime, timeFreq string, opts ValidateSeriesTimeOptions) error

ValidateSeriesTime will return an error if the SeriesTime's intervals don't match timeFreq.

Types

type GuessTimeFreqOptions

type GuessTimeFreqOptions struct {

	// Hint can be set if you have some idea what timeFreq may be.
	Hint string

	// R is used to limit the range of the Series.
	R *dataframe.Range

	// DontLock can be set to true if the Series should not be locked.
	DontLock bool
}

GuessTimeFreqOptions configures how GuessTimeFreq behaves.

type MissingValueOption

type MissingValueOption int

MissingValueOption sets how the ValidateSeriesTime behaves when a missing (nil) value is encountered.

const (
	// Tolerate will ignore a missing value.
	Tolerate MissingValueOption = 0

	// Replace will replace the missing value with a valid time.Time.
	Replace MissingValueOption = 1

	// Error will generate an error if a missing value is encountered.
	Error MissingValueOption = 2
)

type NewSeriesTimeOptions

type NewSeriesTimeOptions struct {

	// Size determines how many rows are generated.
	// This option can't be used with Until option.
	Size *int

	// Until is the maximum time in the generated Series.
	// This option can't be used with Size option.
	Until *time.Time
}

NewSeriesTimeOptions sets how NewSeriesTime decides at which row to stop.

type NextTime

type NextTime func() time.Time

NextTime will return the next time in the sequence. You can call it repeatedly to obtain a sequence.

type TimeGenerator

type TimeGenerator func(startTime time.Time, reverse bool) NextTime

TimeGenerator will create a generator function, which when called will return a sequence of times. The sequence will begin at startTime. When reverse is true, the sequence will be backwards.

func TimeIntervalGenerator

func TimeIntervalGenerator(timeFreq string) (TimeGenerator, error)

TimeIntervalGenerator is used to create a sequence of times based on an interval defined by timeFreq. timeFreq can be in the format: nYnMnWnD, where n is a non-negative integer and Y, M, W and D represent years, months, weeks and days respectively. Alternatively, timeFreq can be a valid positive input to time.ParseDuration.

Example:

gen, _ := utime.TimeIntervalGenerator("1W1D")
ntg := gen(time.Now().UTC(), false)
for {
   fmt.Println(ntg())
   time.Sleep(500 * time.Millisecond)
}

See: https://golang.org/pkg/time/#ParseDuration

type ValidateSeriesTimeOptions

type ValidateSeriesTimeOptions struct {
	// MissingValue configures what must happen when a nil Value is encountered.
	MissingValue MissingValueOption

	// DontLock can be set to true if the Series should not be locked.
	DontLock bool
}

ValidateSeriesTimeOptions configures how ValidateSeriesTime behaves.